Field-magnet structure.



A. J. BROWN. FIELD MAGNET STRUCTURE. APPLICATION FILED APR.19, 1909.

Patented May 23, 1911.

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ARTE UR J. BRONN, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERS COMPANY, A CORPORATION OF NEW JERSEY.

FIELD-MAGNET STRUCTURE.

Specification of Letters Patent.

. Patented May23, 1911.

Application filed April 19, 1909. Serial No. 490,967.

T 0 all whom it may concern:

Be it known that I, ARTHUR'JBROWN, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Visconsin, have invented certain new and useful Improvements in Field- Magnet Structures, of which the following is a full, clear, and exact specification.

My invention relates to dynamo-electric machines, and particularly to alternating current machines of the type in which a rotating field is used. It is especially useful for high speed machines.

Usually in rotating field machines, the pole tips or shoes of the field poles are relied on to keep the field coils in place and to overcome centrifugal force ac ng on the coils. But because of a-compo it of the centrifugal force normal to the at. s of each field pole, the portions of' the coils which are parallel to the shaft have a. tendency to bulge out from the field poles, especially when'thc rotor is running at a high rate of speed.

The 'object of my invention-is to provide a simple construction which will effectively and fully counte'act all effects of centrifugal force on the field windings of projecting pole rotating field machines, and particularly will prevent such windings from bulg- In carrying out my invention I provide bracing plates located, between adjacent projecting poles of a rotating field structure and means interposed between the plates for bracing said plates against the coils on said poles to support such coils.

In the accompanying drawing. Figure 1 is a sectional view of a portion of the rotating field structure of a dynamo-electric ma chine embodying my invention; Fig. is a side view of my br-acing device; and Fig. 3 is a section on the line 33 of Fig. Q.

Mounted in any desired manner on the rim 10 of the rotating member of a dynamoelectric machine, as by means of dove-tails 11. and wedges 12, are projecting field poles 13 provided with the usual insulated field coils 14. Insulating collars 15 are prefer ably placed between the coils and the poletips 21 and spaced from the. latter by rings 16. Insulating collars 17 may also be provided betweenthe field coils and the rim 10. A. pair of bracing plates 19 and 19 is arranged between each pair of poles, and the between these. plates and the coils.

two plates of each pair are forced apart and against the coils on said poles by a screw 18. Proper insulation is provided The screw 18 engages a thread in one of the bracing plates, say 19, and has a rounded head which engages the other of said plates,

the'latter preferably having a hollowed-out portion to receive such head. The plates 19 and 19 are prevented from being thrown radially outward by properly engaging some part of the projecting field magnet; as 1 shown, the plates have inturned end por- .tions 20 which extend under the pole-tips 21. The bracing plates may also be provided with ribs 22, which strengthen the plates and serve as bearing points for the inner ends of the plates. These ribs are also arranged to overlap so as to prevent relative edgewise movement of the plates. After the poles and coils are in place, each pair of bracing plates 19 and 19 is inserted between two adjacentpoles, the screw 18 being properly lowered into the-plate 19. Then by rotating the screw 18 to raise it out of the plate 19, the two plates'are forced apart against the coils and the inturned ends 20 are brought under the p0le-tips 21. Vhen 'thedesircd degree of bracing is obtained the screw is prevented from loosening by means of a cotter pin 23, the hole for which may be drilled after the parts are in place.

With the arrangement shown, the field coils 14: and the bracing plates 19 and 19 are prevented from moving radially outward by the engagement of the inturned end portions 20 with the pole-tips 21, while the coils are prevented. from bulging by means of the plates 19 and 19 and screws 18.

Manynnodifications may be made in the scribed, and I aim in my claimsto cover all modifications which do not involve a departure from the spirit and scope of my. invention.

\Vhat I claim as new is 1. I the rotating member of a dynamoelectric machine, the combinationof projecting field poles, coils thereon, bracing plates against the coils on the adjacent poleSand 110 arrangement here specifically shown and de- 1 coils, said bracing plates having ribs to prevent. a relative edgen'ise movementbetween said plates, and means interposed between said plates for forcing them apart against the coils.

3. In-a dvnamo-cleetric machine, thecomoination of field poles, coils thereon, bracing plates c053 rotating, with said coils to prevent their di placement, said plates having g'frojecling portions cooperating with said poles to prevent displacement of gaging POI'IlODslO prevent a relative edgexvise movement between said plates, and plates into engage plates to prevent displacement of said c means for ,t'orcing the nicnt-n'ith said coils,

t. in the rotating n1(fll)l.1t?l,0'f a dynamoelectric machine, the combination of proplates having intnrned ends, said plates having ribs on one side arranged to prevent a relative cdgcwisc moven'i'ent between said plate: plates for forcing them apart, against the coils on adjac nt poles and their inturned ends under the pole tips of said poles.

3. in the rotating men'iber of a dynamoclcclricunachinc, the con'ibination of? of the ease in, the Patent Office.

[seas] portions under the pole i, jecting field poles, coils thereon, brac-' 1 bination of a rotatable field structure and means interposed between said printed specrhcation requiring collection as tollows. lage poles, coils thereon, a pair of bracing" plates between every two adjacent poles and having means to prevent a relative cdgewise movement between said plates, said bracing plates having intiurned ends, and means interposed between said plates for forcing them apart against the coils on the adjacent poles.

6. In a dynamo-electric machine, the comprovided \vith PIOJQOtlDg held poles, coils on said poles, bracing plates having mtarned ends coiipcratingwith the field structure to prevent displacement of said plates due to t the action of centrifugal 3 also having force, saidplates engaging portions to prevent a relativemlgenase movement between the the plates due to centrifugal action, and alsohavlng ensaid plates having meansto prevent a rclative edg cwise novement between said plates, jcctin'e tield poles, coils thereon, two bracing I and means tor t'orcingrsaid plates into intij ma'tc contact with said'coils.

AIKEHUR J. BR G ll ift.

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It is hereby certified that in Letters Patent No. 992,8 tt5, granted May 23,' 191i, upon the application of Arthur J. Brown, of lvlihvaukee, Wisconsin,

' 'or an improvement in Field-h lagnet Structures, an error appears in the 1, line lOZ, the word cml r-iein should read 571106721 and that the said Letters Patent should he a.- read with thrs correction therein that the same may coniorm to the uncut Signed and sealed this 27th day of June, A. 1)., 1911.

c. e. anaanes,

Acting Commissioner of Eazfenta. 

